Pollard, Andrew

Abstract [en]

Direct numerical simulation (DNS) of turbulent isothermal-wall bounded flow subjected to favourable and adverse pressure gradient (FPG, APG) at low Mach number is investigated. The FPG/APG is obtained by imposing a concave/convex curvature on the top wall of a plane channel. The flows on the bottom and top walls are a tripped turbulent and laminar boundary layers, respectively. It is observed that the flow reaches equilibrium in the FPG region and the first and second order statistics are strongly influenced by the pressure gradients. For FPG/APG regions very near the bottom plane wall, the correlations between the streamwise pressure gradient and the spanwise vorticity flux and between the spanwise pressure gradient and the streamwise vorticity flux in the wall-normal direction are high on the wall and quickly drops to a negligible value within the viscous sublayer. Related flow physics and linkage to energy balance transport is discussed.